Just tested with TF-100, what to do now?

Aneley

Member
Jul 18, 2023
15
Bryn Mawr, PA
Pool Size
19455
Surface
Plaster
Hi,

I just moved to a house that has a salt water pool. Unfortunately, I have zero experience with caring for pools, but hoping to figure it out with some help. I saw the suggestion on this website to get a TF-100 test kit, and just used it on my pool. Considering the results and that this is a salt water pool, what chemicals do I need to buy and how much of them should I add to the pool to get my numbers back to normal? Thanks so much for your help!
Results:
Chlorine: 0.5 ppm
pH: 8.2+
Total chlorine: 4
Calcium Hardness: 450 ppm
Total Alkalinity: 110
CYA: 20+ ppm
Salt test: 4000 ppm
 
First question: have you downloaded pool math? The answer to how of each to add is there.

Second question: your cya, is it 20 or is it higher? The test is awful and difficult to read (at least for me anyway). So, we assume the next highest level is correct when testing then base the FC off of the cya/fc relationship which is discussed here: Free Chlorine and Cyanuric Acid Relationship Explained

For a cya of 30 (based on 20+) Fc should be maintained at 3-6 ppm. For you, that means adding a half a gallon of 10.5% liquid chlorine. Do this NOW. Your current level of cl is dangerously low and could result in algae of its not already there and judging by your combined chlorine, it may have already started so you probably need to slam.

Read up on slam here: SLAM - Shock Level and Maintain

Don't worry abou the other numbers yet , instead adjust your ph 7.4-7.6 and begin the slam proceess.
 
Results:
Chlorine: 0.5 ppm
pH: 8.2+
Total chlorine: 4
Good advice from WJ so far, but before you begin SLAM, can you confirm a couple of test results:

FC: Free Chlorine
CC: Combined Chlorine

Ignore Total Chlorine. That is the sum of FC and CC.
 
  • Like
Reactions: Mdragger88
Hi,

I just moved to a house that has a salt water pool. Unfortunately, I have zero experience with caring for pools, but hoping to figure it out with some help. I saw the suggestion on this website to get a TF-100 test kit, and just used it on my pool. Considering the results and that this is a salt water pool, what chemicals do I need to buy and how much of them should I add to the pool to get my numbers back to normal? Thanks so much for your help!
Results:
Chlorine: 0.5 ppm
pH: 8.2+
Total chlorine: 4
Calcium Hardness: 450 ppm
Total Alkalinity: 110
CYA: 20+ ppm
Salt test: 4000 ppm
For your chlorine testing, ignore the yellow OTO test if it came with that. Use the FAS-DPD which is the powder that turns the water pink when chlorine is present. I don’t remember if the TF-100 came with OTO so just highlighting that since you recorded a total chlorine.

Or is it possible you made a typo and your free chlorine(FC) is 4ppm and your combined chlorine (CC) is 0.5ppm?
 
Hi, welcome to TFP! You can download a free version of the app to your phone or you can use the version of PoolMath from the website. Set up your pool, plug in your test numbers and the app will tell you how much of each chemical you need to add.
As far as what should be tackled first.... I want to make sure we are speaking the same language so I am asking some questions about your test results. A total chlorine of 4 with a free chlorine of 0.5 would mean you have combined chlorine of 3.5 If you have 3.5 of combined chlorine the first thing you will need to do is slam the pool if you have reported your test results correctly. Combined chlorine (CC) is the waste byproduct of chlorine oxidation. CC is harsh smelling and can irritate the skin and eyes. Completing the SLAM Process will get rid of the CC and any organic waste in the pool. You want CC to be 0.5 or less. 1.0 or higher indicates a need to slam.

I'm assuming that since you say you have a salt pool that you are using a salt water chlorine generator? If so you need to bump up the CYA to 60ppm and raise the free chlorine (FC) to 3ppm. It is best to use liquid chlorine to raise the pool to the target level and then use the SWG to keep the FC level at the top of the target range.

While you are raising the CYA and FC you will need to work on bringing the pH level down to around 7.5
 
Good advice from WJ so far, but before you begin SLAM, can you confirm a couple of test results:

FC: Free Chlorine
CC: Combined Chlorine

Ignore Total Chlorine. That is the sum of FC and CC.
Sorry, I had this:
5 drops x 0.5 = 2.5 ppm Free Chlorine
3 drops x 0.5 = 1.5 CC
Total chlorine = 4
Thanks for the help!
 
  • Like
Reactions: Rancho Cost-a-Lotta
For your chlorine testing, ignore the yellow OTO test if it came with that. Use the FAS-DPD which is the powder that turns the water pink when chlorine is present. I don’t remember if the TF-100 came with OTO so just highlighting that since you recorded a total chlorine.

Or is it possible you made a typo and your free chlorine(FC) is 4ppm and your combined chlorine (CC) is 0.5ppm?
Okay, thanks! Here was my math:
5 drops x 0.5 = 2.5 ppm Free Chlorine
3 drops x 0.5 = 1.5 CC
Total chlorine = 4
 
CC >=1 Time for a SLAM.

Print this out (link at the end), read it three times and go! Link-->SLAM Process

Season 1 Showtime GIF by The Chi
 
Can you confirm your cya?
Was it between two values?
How does the water look? Is it Cloudy? Any visible algae?
Currently, tonight, you need 2 things-
Liquid chlorine- asap - to reach
SLAM Process fc level for your cya (let’s confirm what you mean by 20+)
FC/CYA Levels
& Muriatic Acid to get ph back in the 7’s.

PoolMath can calculate amounts for you.

If you’re going shopping you will also need some dry cya/stabilizer for after you deal with your slam. You don’t want to raise it yet.
Around 6 # or so eventually, it usually comes in 4# bags so you’ll need 2 bags.
 
  • Like
Reactions: Rancho Cost-a-Lotta

Enjoying this content?

Support TFP with a donation.

Give Support
Can you confirm your cya?
Was it between two values?
How does the water look? Is it Cloudy? Any visible algae?
Currently, tonight, you need 2 things-
Liquid chlorine- asap - to reach
SLAM Process fc level for your cya (let’s confirm what you mean by 20+)
FC/CYA Levels
& Muriatic Acid to get ph back in the 7’s.

PoolMath can calculate amounts for you.

If you’re going shopping you will also need some dry cya/stabilizer for after you deal with your slam. You don’t want to raise it yet.
Around 6 # or so eventually, it usually comes in 4# bags so you’ll need 2 bags.
I found the CYA a bit confusing. It was basically at the top of the beaker at 20 but there was no room to fill it any higher and I could still see the black dot. So I put 20+ because I assume it needs to be taller to fill higher to lose sight of the black dot. It was my first time doing this test, so not certain I did it right. But I'm assuming I shouldn't see the black dot at all?
The water actually looks pretty clear to me. No visible algae.
Thankfully the previous owner left some bottles of liquid chlorine, so will SLAM asap. Then I will purchase muriatic acid. Is there a certain muriatic acid that works better? And how do I know how much to add?
Thank you for your help!!!
 
Follow these instructions for CYA:

Chlorine degrades, you may find it to be ineffective.

Look in the garden or paint section and look for 31.45% or 20 Degree baume Muriatic.

On how much of everything to add, download pool math, setup your pool and it will help you. Link-->PoolMath
 
I found the CYA a bit confusing. It was basically at the top of the beaker at 20 but there was no room to fill it any higher and I could still see the black dot. So I put 20+ because I assume it needs to be taller to fill higher to lose sight of the black dot. It was my first time doing this test, so not certain I did it right. But I'm assuming I shouldn't see the black dot at all?
This means you have less than 20ppm cya- you’ll need around 30ppm for now or your fc will be gone rapidly due to the sun.
The water actually looks pretty clear to me. No visible algae.
That’s good 👍🏻 let’s keep it that way!
Thankfully the previous owner left some bottles of liquid chlorine, so will SLAM asap. Then I will purchase muriatic acid. Is there a certain muriatic acid that works better? And how do I know how much to add?
Thank you for your help!!!
Use
PoolMath
 
Follow these instructions for CYA:

Chlorine degrades, you may find it to be ineffective.

Look in the garden or paint section and look for 31.45% or 20 Degree baume Muriatic.

On how much of everything to add, download pool math, setup your pool and it will help you. Link-->PoolMath
Turns out I was interpreting it wrong and my CYA is >20.
I'm having trouble finding that online. Do you think acid blue or acid magic off Amazon would be okay?
Thank you!
 
So I downloaded the pool math, but I can't seem to figure out how to use it. I don't know the information on my SWG, since the previous owner's didn't really leave me with that information. Really finding this confusing
 
I'm having trouble finding that online. Do you think acid blue or acid magic off Amazon would be okay?
Where are you in PA, city and zip. I'll find you a source. Don't ever buy anything with Blue/Blu in the name and put it in your pool. Full Stop. Any Chemical.
So I downloaded the pool math, but I can't seem to figure out how to use it. I don't know the information on my SWG, since the previous owner's didn't really leave me with that information. Really finding this confusing
Go out to the cell and take pictures of the cell and the controller. Particularly labels, maker and part numbers, we'll figure it out.
 
Turns out I was interpreting it wrong and my CYA is >20.
I'm having trouble finding that online. Do you think acid blue or acid magic off Amazon would be okay?
Thank you!
Don’t use that stuff, it’s overpriced lower concentrated. Use regular muriatic acid from Home Depot, etc.

Edit: hang on. Cyanuric acid is not the same as acid for pH.

Cyanuric acid = stabilizer=CYA. This is used to protect the chlorine and is what dictates how much chlorine you need in the water.

Muriatic acid = the stuff that lowers your pH.

It’s maybe a little confusing now, but you’ll get it and people around here will help.
 
Where are you in PA, city and zip. I'll find you a source. Don't ever buy anything with Blue/Blu in the name and put it in your pool. Full Stop. Any Chemical.

Go out to the cell and take pictures of the cell and the controller. Particularly labels, maker and part numbers, we'll figure it out.
Thank you!! I'm in Bryn Mawr 19010. I'll take some photos of it tomorrow in the daytime, thanks again
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.